


On My Side

by camichats



Category: Marvel
Genre: Alternate Universe - Canon Divergence, Captain America: Civil War (Movie), Established Tony/Natasha, F/M, Getting Together, M/M, Multi, Past Steve Rogers/Tony Stark, Polyamory
Language: English
Status: Completed
Published: 2018-09-09
Updated: 2018-09-09
Packaged: 2019-07-08 21:18:13
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,839
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15938486
Author URL: https://archiveofourown.org/users/camichats/pseuds/camichats
Summary: Tony was expecting Natasha to break up with him when they were presented with the Accords. He wasn't prepared for what ended up happening.





	On My Side

**Author's Note:**

> Many thanks to [periwinklepromise](https://archiveofourown.org/users/periwinklepromise/pseuds/periwinklepromise) for editing this fic for me

When the Accords came into view, Tony's heart sank. Ross was bad enough, but something like this? Tony knew it would happen at some point, but when did this get put together? Tony hadn't heard head nor tails of this, but he could easily admit that with his break-up with Steve, the whole mess with Ultron trying to destroy the world, and Jarvis being killed, he hadn't paid much attention. Obviously they'd kept it under wraps for no one to have heard whispers of it until they were all expected to sign a week from now.

He felt like he was going to be sick. Dating Steve had been great, and he cared about him, but by the time it ended, he realized that it had been the natural conclusion to the hero worship he'd done as a kid. Dating Natasha though? That was something else entirely. He could see a future with her. Oh he was careful not to get too clingy for fear of scaring her off, and he didn't hint at wanting something more permanent for the same reason. He fucking loved her, and now they were going to break-up, not because of something he did wrong, but because Ross cleaned up and wanted to make a new name for himself in the political world.

Knowing that Ross was a dick didn't change how he thought about the idea of the Accords though. Ross left, and they started to talk about it amongst themselves, the Avengers, the people he used to trust to have his back no matter what. He said they should sign, and Rhodey said they should sign; that wasn't a surprise. When Natasha agreed though, he was shocked.

**"At least this way, we can keep one hand on the steering wheel**."

Tony swallowed down a completely unwelcome and inappropriate marriage proposal.

* * *

They were at the airport and fighting for some goddamn reason that Steve seemed to know but wasn't sharing. Natasha, fortunately, had _some_ idea about what Steve was talking about, because later she let him and Barnes through to the jet. Tony thinks 'fortunately' because he didn't want to think about what would have happened to either of the super soldiers if she hadn't.

She was technically under arrest, same as Steve had been earlier-- god was it the same day?-- but she wasn't in cuffs or thrown in a cell, and that's all Tony could think about. She was arrested, but she wasn't _arrested_ and that was going to have to be enough.

Tony had just ended a call, and he felt completely hopeless about the situation. No one wanted to listen; no one wanted to remember that five years ago they would have given their soul to suck Captain America's dick. He was standing, hands on the table, and shoulders hunched in defeat.

That was how Natasha found him. "You're mad at me," she said, voice a practice in calm and collected.

Tony startled, turning to see her leaning against the doorframe. Not in the room, hovering at the edge in case he told her to get out and she actually decided to listen. He sighed, turning to face her fully and leaning against the table's edge. "Why do you think that?"

"I betrayed you."

"Did you?"

"Don't do that Tony," she said wearily, stepping inside and closing the door behind herself.

"Don't do what? For once I am not doing anything. You didn't betray me, you were trying to keep the team from beating the shit out of each other."

"I told you that I was there on your side. And then I wasn't."

Tony shrugged one shoulder. "So you're morally dubious, whatever. I've known that for a long time."

Natasha searched his face. "You really don't think of it as a betrayal, do you?"

"Nope. And I'm not mad at you, I'm annoyed. If you hadn't helped them, I wouldn't have to be trying to pull your ass out of the fire right now."

"Sounds to me like you should be mad not just annoyed."

"Mad would be if I actually wanted to catch and punish Steve."

"And you don't?"

"Something's going on. Something I missed because I was focusing on the wrong parts. What is it?"

Natasha stared at him evenly. "I don't know," she said honestly. "Something to do with the Winter Soldier."

Tony made a noise of pure frustration, but before he could say anything else, Natasha spoke again.

"Sam should know. He was trying to go with them, there's no way he doesn't know at least where they're going."

Tony nodded, grabbing his jacket and putting it on before he realized something and wrinkled his nose in disgust. "I hate the Raft."

"If you liked it, you would be closer to villain than hero."

"Eh." He tucked his phone in his pocket and headed for the door, pausing with his hand on the knob when Natasha called out to him. "Yeah?"

"Am I going to have a boyfriend when you get back?"

"Unless you've changed your mind." He glanced back at her. "Have you?" She shook her head, looking oddly open. Not vulnerable, never vulnerable in a building run by people she didn't trust. "Then we're fine." He waited until she nodded in acknowledgment before he left.

* * *

The next time he saw her, it was with the halo of dull white hospital walls and a pinched look on her face. He was parched with a fuzzy feeling in his mouth and a forced floating feeling to his head, reminiscent of his party days when he took drugs and didn't bother to get home or otherwise take care of himself. Talking past all that was like riding a bicycle-- easy to do when you tried it again. "Hey gorgeous," he croaked.

Natasha's head jerked up, and she leaned closer to him. "Tony. How do you feel?"

"Thirsty."

She grabbed a cup of water and helped put it into his IV-free hand. When she was sure he had a grip on it, she let go slowly and sat back down.

Something in his motor control or perception was messed up, and he ended up spilling some water on himself. It felt freezing on his neck where it dripped down, and that triggered shivers. God he hadn't noticed he was so cold until he got wet, but now it was all he could think about.

Next thing he knew, there was a blanket covering his body, and Natasha was holding his head to her chest, telling him that he was okay now.

* * *

"I'm going to kill them."

Tony sat heavily in the armchair instead of joining her on the couch. The couch was hard to balance on when he had injuries, and as it stood he'd pulled on the deep bruise that made up most of his chest when he sat down anyways. "Not even a hello first? Straight to the murder. Whatever works, I guess, but I think I would prefer the greeting."

Natasha's eyes were cold when she looked at him, and she tossed a tablet on the table between them. It landed with a hard clatter, the screen paused on a video. Tony couldn't tell what it was because it looked to be dark and of rather poor quality.

"I can bust out the gaming console," Tony said when she didn't explain. "Shooting people virtually is the same as shooting them in real life if you listen to some people talk, maybe it will feel the same too."

Natasha ignored his rambling, which was fair as he was still on pain medication and he wasn't entirely sure that what he said made sense. "Do you know what this is?" she asked, nodding at the tablet-- or, more accurately, the video.

"The opening credits to the last Harry Potter movie?"

"It's footage."

Tony's eyes shot to the screen, but it wasn't showing the road. He looked back at her.

"Friday found out that you didn't tell me what happened in Siberia with Rogers and Barnes."

Tony raised an eyebrow, ignoring the pounding of his heart. "Since when is he 'Rogers' to you?" This whole time, he'd remained 'Steve'. From Tony's hospitalization, to the Accords being pushed to the back burner and getting a hefty edit, to Rhodey's recovery, the beloved Captain had always been Steve to her.

"Since he nearly killed you."

Tony held her gaze evenly while his stomach lurched and churned. "He had every right."

"No, he _didn't_. Why do you let people do this to you, Tony? First Maximoff, then me, and now him?"

"You're not the same as them," he said. His ears were ringing. That wasn't her point and he knew it, but he couldn't let her group herself in with the two of them, even for a second.

"I'm glad you think so. I'm still going to kill them."

Tony sighed, dropping his head back and staring at the ceiling. He wondered why they surrounded sick people in such a garish shade of white. "And how exactly do you plan to kill Maximoff? Like it or hate it, she's got powers, and you don't. I don't want you to get killed on a fool's errand."

"Don't worry," she said, standing up to brush a kiss to his forehead. "I won't." With that, she headed for the door.

Tony panicked, reaching out to her. "Wait!"

She paused and half turned back to him.

"You're- you're leaving?"

Natasha turned to face him fully, and then her shoulders relaxed. "I guess it can wait a couple days."

* * *

He was still in the hospital by the time she left, and she was careful, this time, to not tell him what her plans were again. He was stuck in bed for another week, and they wanted him to stay for another couple days for 'observation'. Tony told them he was just as observable at the Avengers Compound and his Tower as he was here. Friday even had it written into her coding that she had to contact other people if Tony was in need of medical attention because of what had happened with the palladium poisoning with Jarvis (who had been _very_ upset with him after that and gave him something of the silent treatment after the Expo fiasco was finished).

They relented, but Tony thought that had more to do with Rhodey and Fury than anything he'd done. Whatever. With everything else going on-- mainly his and Rhodey's respective recoveries-- he wasn't going to bitch about it.

There was plenty else to bitch about. Like how the press was trying to hound the remaining Avengers just so they could get a photo of them being sad, or maybe, if they were lucky, a statement about how downtrodden they felt with only three of them left, and did they even count as three? Black Widow was MIA (but only really missing for the public, she wasn't actually off the grid), and Iron Man was down with injuries. War Machine was moved up to fulltime Avenger along with Spiderman, but the press was being such a giant-ass dick about _that_ that it hardly mattered. Vision was doing well, at least. He referred to his flirtation with Wanda as a "painful, but ultimately enlightening experience" that was necessary to his growth as a person.

It was about a month after Natasha left that she suddenly showed back up. 'Showed up' meaning that she contacted Tony. Friday was vetting all of his calls, turning away all manner of unpleasantness on his behalf, and she put Natasha through-- not that she told him who it was, the little trickster.

Tony was in the little workshop in the Compound when it happened. He was still stiff from his injuries, and he didn't have his full range of motion, so he was moving slowly and not lifting anything heavy. It was like he was a kid again, only Howard wasn't there to tell him not to try anything dangerous, so he had to remind himself of it like a goddamn bonafide adult. He answered without a second thought, both because he trusted Friday and because he was focusing on getting his grip tight enough on the wrench that it wouldn't fall on his foot if he tried to use it. At least phone calls were hands-free with Friday around. "Hello?"

"Hey Tony," she said.

Tony paused, then set the wrench down. "Hey. Are you... in trouble?"

She huffed out a surprised laugh. "No, no nothing like that."

"Oh. Then why are you calling?"

"What I can't miss you?"

"Nat."

"Yeah alright," she said easily. "I'm done, but I was about to come up with a passenger who might not be welcome so I wanted to check with you first."

"Uh, passenger as in companion or kidnapee?" He had to check because sometimes she used euphemisms like that and he was completely blindsided.

"Companion," she said, sounding amused. "I went to talk to Rogers and wound up getting friendly with Barnes."

"...You're with Barnes?"

"Yeah. The princess of Wakanda-- Shuri, you'll like her, she's really smart-- fixed him up, and he explained what happened. He wants to apologize."

"You brought him home with you because he wants to apologize?"

"It's not the sole reason," she said, and Tony's heart sank. He knew that she and the Winter Soldier had history, but he didn't know if that history was good or bad. Until now, apparently, because if she was so ready to believe him, that meant it was good, which meant that Tony was screwed-- on a romantic level, that is. He didn't think that Natasha would ever bring someone around if they were going to hurt him. "Do you want to talk to him?" she asked, pulling him out of his thoughts.

"If I say no, what would you do?" he asked curiously.

"I'd ask you to take some time to reconsider, but presumably you would insist that you didn't need time, and then I would tell you that I'll see you as soon as I drop Barnes off somewhere safe."

"Why are you still calling him Barnes if you're all buddy-buddy?"

"For you," she said simply. "So do you want to talk to him?"

Tony sighed. "Sure, put him on."

There was silence, the sound of some shuffling, and then Barnes saying, "Stark?" in his ear, all hesitant.

"I'm listening."

"I'm sorry about your parents. And attacking you."

"I attacked you first."

"You had every right," he said, and he sounded so sure about that that Tony was taken aback. "I... wish I things had been different. Between us. Natalia only has good things to say about you. I would have liked to been considered your friend." He gave a bitter laugh. "Guess that's behind us now though, right?"

"I'm pretty sure there's a saying about chickens and eggs that is applicable right now."

"What?"

"You're forgiven."

"But-"

"Do you want to be forgiven or not?" Tony said, steamrolling over him.

"I- I don't know," he said quietly.

"Well you can figure it out on the plane."

"What?"

"Or the car ride if you're already in state. I don't know where you guys are, after all."

"I'm confused," he admitted, voice small.

"I have that effect on people, don't worry about it. You want to hand the phone back to Natasha? She has a degree in dealing with my bullshit, she got it from Pepper."

"Okay," he said slowly, clearly not any less confused than before.

Some more shuffling, and Natasha was back on the line. "What did you say to him? He looks a like a sad puppy, Tony. Ooh now a slightly upset sad puppy. There, there," she said, and Tony would bet good money that she was patting Barnes's head. "So what's happening? Are we seeing you soon or...?"

"Yeah. How long is it gonna take you to get here?"

"Couple days maybe. We're in Eastern Europe right now, and it's pretty hard to get to the States right now."

"Fun. Let me know if you need any help."

"Will do. Love you, see you soon," she said, and ended the call.

Tony froze, wishing he had a phone screen to stare in bewilderment at. "Fri?"

"Yeah boss?"

"Did... did she just tell me that she loves me?"

"That's what it sounded like. Maybe you should buy her some Andes as a thank you."

"Did you seriously just tell me to buy her chocolate as a _thank you_?" And not even a fancy chocolate at that. He liked Andes of course, but anyone could buy them from a dollar store if they wanted to.

"Unless you want to say it back. I wouldn't recommend ignoring it entirely, boss. That seems like a good way to hurt her feelings."

Tony peered at the ceiling suspiciously. "You and Vision have been talking again haven't you."

"You didn't say we couldn't. Are you revoking our talking rights?"

"No," Tony said, rolling his eyes. "But you, little missy, should stay away from romantic relationships, they're nothing but trouble."

"Jarvis helped you," she pointed out.

As always, thinking of Jarvis made his heart restrict, but it was getting more distant now. The pain of a lost friend that he didn't think would ever go away, not the stabbing-in-the-heart pain he used to feel every time Friday's voice came out of the speakers instead of Jarvis's. "Yeah, and look at how well me and Steve turned out."

"This sounds more like a criticism of you and Jarvis than me and Vision," she pointed out, and unfortunately she was right. About him, that is, not Jarvis. Jarvis had every reason to believe Steve would be for him-- that they would be good for each other-- and it wasn't his fault that he was wrong.

"Maybe so," Tony muttered. "Look Friday, you and Vision can talk about whatever you want, just leave me out of it. If I'm going to fuck up my relationship, I want it to be only my fault."

"As you say, boss."

* * *

Tony added Barnes to the list of approved people, and there was little fanfare when he and Natasha came home. That is to say, they snuck in and Tony didn't know they were there until he went to grab some lunch and saw them in the kitchen.

Natasha was overly casual about it, probably to offset the suddenly tense supersoldier that was sitting opposite her. "Hey Tony. How have things been since I last saw you?" she asked, a hint of apology to her voice, not that Tony blamed her in the slightest for being gone-- how could he?

Tony shrugged, going to the fridge and opening it up to see if anything looked appetizing. "Ross is no longer a pain in my ass, he's a pain in Rhodey's ass."

"How is he?" Barnes asked quietly and quickly, like his goal had been to stay as invisible as was possible in the brightly lit room only his mouth ran away from him.

Tony very carefully didn't tense up at the question, knowing that he didn't mean anything bad by it. "Pretty good. He's not taking his early retirement from the Air Force very well, but he thought he'd be there another twenty years, so." Tony shrugged again. "Helping out here is helping, I think. Either that or he doesn't want Vision to feel bad about his inability to cook; it could go either way. That's a thing, by the way. Helping Vision learn about humans. If you're going to stay-- which I think you should-- be prepared to answer all sorts of weird questions for him."

Barnes gave him a tentative smile. "I will." He glanced at Natasha, who gave him an encouraging nod.

Tony went back to looking at the fridge's contents and wrinkled his nose. "Ugh. Who buys this shit," he said, letting the door go so that it closed by itself.

"Pretty sure you're in charge of that," Natasha said.

"Bleh." He turned to face them and rested his butt against the counter. "What were you guys planning on having?"

"Soup. Bucky was going to teach me a recipe."

Tony nodded.

"Do you... want to join?" Barnes offered hesitantly.

"Sure."

Barnes's smile came easier this time, and looked more real. Tony's heart thumped, and he told himself it was from lingering fear and nothing else.

* * *

Barnes became Bucky, and Tony's heartbeat turned erratic around him, incidentally whenever he smiled or looked cute or something like that. It was time to admit that he was attracted to him, because his other options were major heart problems and near constant panic attacks.

Falling in love in a month wasn't exactly out of character for him, but doing that while also dating someone he loved, was.

Not that he and Natasha were very couple-y these days. Or- they _were_ but Bucky was there for all the dates. And instead of having sex at the end of the night, the three of them would all shuffle off to their separate rooms with variations of guilt and longing the only thing keeping them company.

Tony knew it was only a matter of time before he was phased out of the 'date nights' so that it was just Natasha and Bucky. He had to hand it to them though-- this was as smooth a transition as he could possibly hope for.

* * *

One night, Natasha asked to talk to him, and Tony walked into the room to see her and Bucky sitting side-by-side on the coffee table, obviously nervous and expecting Tony to sit in the armchair opposite them. Now that it was finally happening, he felt oddly detached from the situation. The sort of detached that meant he would be a crying mess once he was alone.

Tony flopped into the chair, body surprisingly loose for all his insides were a tense, twisting mess. "What's up?"

They shared a look before turning to him fully. Bucky licked his lips. "Uh, Tony we were thinking about our- situation. With the three of us," he said haltingly.

"Yeah, I figured."

Bucky's face pinked. "Um. Yeah. So you're... okay with it?"

"Course." He stood up and pat Bucky's shoulder as he passed. "No hard feelings, right?"

"What?" Bucky said dumbly as Tony started to leave the room.

"Tony," Natasha piped up, making him pause, "what do you think we just told you?"

He half-turned towards them. "That you're together? Seriously Nat, it's fine; I get it."

"Tony," she said again, getting to her feet and walking towards him, but stopping with several feet still between them. "We didn't team up for me to _dump_ you. Jesus." She rubbed at her forehead with one of her hands, the other on her hip. She dropped her hand to her side and pinned Tony with a stare. "Tony, I love you. I know the first time I told you was over the phone, and I didn't give you a chance to respond and we haven't talked about it since I got back. Or- you know, at all, but I do. I love you. I'm not leaving you. And if I ever were to to do that, and I wouldn't bring along a fucking audience."

Bucky hovered awkwardly in the background, still not good with emotional situations unless they happened in the dead of night when everyone was too tired to think about it.

"I wouldn't do that to you, and neither would Bucky."

Tony wasn't saying anything, but he also wasn't leaving. Bucky took it as a good sign and stepped up to him like Natasha was, but more evenly spaced so that this time it felt like the three of them instead of him and Natasha against Tony like it had been before. "I like you," he admitted quietly, but the only other sounds in the room were their breathing and the hum of electricity so it was comparatively loud. "I- talked to Nat. Told her how I felt about you. And she suggested that we... give it a try."

"Try what?" Tony asked, looking between the two of them cautiously.

"The three of us," Natasha said. "Together. At once."

"I've seen porno that started like this," he said automatically. "Although I think they usually went with two girls instead of two guys."

"You still into it?" Bucky asked.

"I- shit," he said, slumping over.

Bucky and Natasha both rushed to his side, and it felt like there were hands all over him, comforting not confining though so he was able to breathe easy.

"Fuck I've been bracing for _months_ , Nat."

"For me to suggest a threesome? Well, polyamorous relationship if you want to get technical."

"For you to break up with me. It's a fucking miracle that we lasted this long, and now- jesus I need to sit down." They guided him to the couch, blanketing him on either side.

None of them said anything for a while, waiting for Tony to calm down. Except then he was calm and all of them were sitting there in an uncomfortable silence even as they continued to cuddle on the couch. Bucky was the one to talk first. "I'm sorry if I made your life worse," he said quietly.

"Don't give yourself that much credit," Tony mumbled, turning his head into Nat's stomach. She put her hand on his head and started carding her fingers through his hair. He took a deep breath. "Okay. So. The three of us dating? That's what you wanted to talk about?"

"Yeah." Natasha sighed, Tony's head rising with the swell of her stomach as she did. "But not if you don't want it."

Tony snorted. "Are you trying to tell me that your collective spy powers died, and you don't already know the answer to that?"

"Spy powers are on a vacation right now, please answer the question as if to a baseline human," Nat said, jokingly pitching her voice like a computer recording.

Tony laughed for a second, then pressed his face more fully against her stomach, making her grunt at the pressure. He eased off when he heard her make that noise. "You know that I want to."

"I didn't know," Bucky said. "If that helps."

"Helps a little."

Bucky pat his leg.

"So we're dating now?" Tony asked.

"Looks that way," Natasha said. "Want to go celebrate?"

"Nat," Bucky chastised, obviously worried that she was being too forward.

"Yeah, I'm afraid I have to side with Buckaroo on this one. I missed you, but I just... I can't. Yet. Sorry."

"Nothing to apologize for kotyonok," she said gently. "I was only teasing. Well- maybe not _only_ , but I didn't expect you to hop right into bed."

~Epilogue~

Tony told Natasha and Bucky that while he wasn't ready for anything physical yet, they shouldn't let that stop them. They said okay, but Tony knew that they weren't doing more than what Tony saw-- which was pretty much reserved to the occasional peck on the lips and a lot of PG cuddling.

He also learned that while they were superspies, they weren't always good at reading him. Because while he thought it was incredibly obvious what he meant when he invited them to dinner one night where he cooked a full Italian meal for the three of them, they thought it was just another date-- albeit a fancy, romantic one.

Their dates usually ended with them nearly falling asleep on the couch while watching a movie, so it wasn't a surprise when Tony pulled them to the couch. He waited five minutes and thirty nine seconds for one of them to make the first move-- yes, he was counting-- but neither of them did, and what little patience he had ran out.

He threw a leg over Bucky's lap and straddled him, pulling him into a kiss so filthy Natasha felt like she was watching porn. Bucky sucked in a breath but kissed him back, hands going to his hips automatically. "Uh," he said dumbly when Tony pulled away to breathe. He glanced at Natasha, who was watching them with wide-blown pupils and a casualness to her posture that meant she was very _very_ interested in what was happening in front of her. "Am I th' only one that doesn't understand what's happenin'?"

"You're not a virgin," Tony growled, "so stop acting like it and take me to bed."

That was invitation enough. Bucky got to his feet, picking Tony up effortlessly.

"You too Tasha!" Tony called, and Bucky heard her scramble to her feet and follow behind him.

Later, when he was _exhausted_ \-- not to mention covered in fluids-- he finally collapsed onto his bed with the intention to sleep. He licked his lips, tasting both Bucky and Natasha there. "You're staying right?" he asked, voice croaky from- well, screaming earlier.

"If you want," Natasha said, rubbing his shoulder.

"Want. Definitely want. Don't go anywhere."

Bucky chuckled and pressed a kiss to his hair. "Got it sweetheart. Not going anywhere."

**Author's Note:**

> In case you didn't know, Andes are mint chocolates that, while delectable, aren't exactly fancy. Especially for a billionaire. 
> 
> Also, I'm on tumblr [@cami-chats](http://cami-chats.tumblr.com)


End file.
